Manganese alloy



Patented May 20,1941

MANGANESE ALLOY Clarence Travis Anderson, Pittsburgh, Pa., assign I or to Chicago Development Company, Chicago, 111., a corporation of Illinois No Drawing. Application April 21, 1939,

' Serial No. 269,213

1 Claim.

This invention relates to the preparation of ductile manganese-base alloys containing aluminum and/or silicon.

Manganese-base alloys containing aluminum and/or silicon have heretofore been prepared from commercial manganese, that is, manganeseprepared by-the alumino-thermic and silico-thermic methods. Alloys prepared from such manganese containing more than about 0.5% of either aluminum or silicon, as determined by the usual methods of chemical analysis, are known to be brittle. Thus, for example, such commercial manganese cannot, at least in most cases, be used for the production of satisfactory alloys'of the type disclosed in the copending applications of James R. Long, Serial No. 140,817, filed May 5, 1937, now Patent No. 2,202,012, issued May 28,

ner, I add'aluminum .or silicon, as metals and essentially free from oxides, to molten electrolytic manganese which has preferably been previously refined in accordance with the processes described in the copending applications of C. Travis Anderson, Serial No. 250,377, filed January 11, 1939, now Patent No. 2,221,622, issued November 12, 1940; and Serial No. 257,455, filed February 20, 1939, now Patent No. 2,221,624, is-

sued November 12, 1940, or other manganese having a purity of at least 99% and preferably higher. The amount of oxides of aluminum and/or silicon introduced into the metal in this way is insuflicient to interfere with the use of the resulting manganese-aluminum or manganesesilicon alloy-in the manufacture of the manganese-base alloys of the present invention. In

1940; Serial No. 199,602, filed April 2, 1938, now

Patent No. 2,216,535, issued October 1, 1940; and in the copending applications of Reginald S. Dean, Serial No. 199,329, filed April 1, 1938, now Patent No. 2,230,236, issued February 4, 1941; Serial No. 219,501, filed July 16, 1938; and Serial No. 230,209, filed September 16, 1938, now Patent No. 2,234,428, issued March 11, 1941. The alloys disclosed in said applications are, in part at least and among other things, distinguished by the use of electrolytic manganese or manganese which contains less than about 0.5% of aluminum and/or silicon.

In accordance with the present invention, manganese alloys are produced containing at least 0.1% but preferably upwards of 1% of aluminum and/or silicon which are ductile and do not exhibit the deficiencies which'have characterized supposedly similar alloys of the prior art. It has been discovered that the objectionable characteristics which are found in commercial manganese and which have resulted in seriously limiting the use thereof in various manganese-base alloys, especially those containing at least 30% manganese, are apparently due to the presence of a substantial proportion of the analytical content of the elements aluminum and silicon in the form of their oxides which are apparently dispersed or dissolved in the molten manganese'and remain so in the solidified metal.

In general, my invention is concerned with the production of manganese-base alloys containing not substantially less than 1% of aluminum and/or silicon, wherein the contents of these metals present as oxides is so small as to exert no deleterious efiect on the ductility and other de- 1 sirable properties of the novel alloys. In order to accomplish this purpose in a highly effective manorder to reduce still further the amounts of the oxides of aluminum and/or silicon, the molten electrolytic manganese may be treated with calcium,. lithium, sodium or magnesium, or their hydrides, before the addition of the aluminum and/or silicon. r

Instead of preliminarily adding the aluminum 'and/or silicon to the substantially pure manganese and then using the resulting product in i the manufacture of the manganese-base alloys,

excellent results are obtained by adding the aluminum and/or silicon to the alloying metals themselves during the process of preparing said alloys or to the previously prepared alloys of the metals other than aluminum and/or silicon.

The following examples are illustrative of the practice of my-invention:v It will be understood that the proportions of metals and'the like may be varied, that other alloying elements may be utilized, and that other changes may be made without departing from the spirit of the invention as pointed out in the appended claim.

Exaniple 1 100 pounds of electrolytic manganese weremelted in an alumina crucible in an induction remainv in molten condition for about ten minutes.

The resulting alloy was then cast into ingots.-

It can be utilized efiectively in the preparation of ductile manganese-base alloys. Instead of silicon, aluminummay be employed, or mixtures of, aluminum and silicon may be utilized.

Example 2 Following the teachingsof my invention, an

Example 3 An alloy was prepared containing 94% electrolytic manganese, 3% copper, 2% nickel and 1 silicon. This alloy possessed a high vibration damping capacity and a; capacity for hardening by heating to 1100 degrees C., quenching, and aging at 750 degrees C. In the quenched or cast state, it was ductile and could be worked by drawing, rolling or hammering.

Example 4 An alloy was prepared containing 72% electrolytic manganese, 16% copper, 8% nickel and g 4% aluminum. The resulting alloy was sufiiciently ductile to be worked and possessed properties quite similar to those of Example 2 hereinabove.

Example 5 An alloy was prepared containing 85% electrolytic manganese, 5% nickel, 5% copper and 5% aluminum. The resulting alloy was ductile, had a tensile strength of 16,000 pounds per square inch in the annealed condition and 95,000 pounds per square inch in the cold worked condition.

Its resistance to high temperature scaling was greater than that of a similar alloy but without aluminum.

The content of aluminum and/or silicon in the alloys, as indicated hereinabove, should be at least 0.1% and preferably upwards of 1%. Good results are obtained with various types of alloys containing from 3% to 5% of aluminum and/or silicon and, for certain purposes, these percentages can be substantially exceeded without adverse efiect upon the ductility and other characteristics desired in the finished alloys.

What I claim as new and desire to protect by Letters Patent of the United States is:

A ductile manganese-base alloy containing from about 0.1% to about 5% of a member selected from the group consisting of substantially oxide-free aluminum and silicon, from about 2% to about 10% nickel, from about 3% to about 16% copper, and the balance comprising substantially electrolytic manganese.

C. TRAVIS ANDERSON. 

